Make build system fall back to matwrapped  Octave bindings if swig is not available.
Make build system fall back to matwrapped  Octave bindings if swig is
not available.

svn path=/trunk/; revision=11488

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot